Stress-based vapor sensing using resonant microbridges

摘要

We demonstrate that silicon-polymer composite microbridges provide a robust means of water vaporndetection at ambient pressure. Volumetric changes in the reactive polymer alter the tension in andoubly clamped structure leading to large and rapid changes in the resonance frequency. Wendemonstrate stress-based sensing of water vapor in ambient pressure nitrogen using doubly clampednbuckled beams coated with a hygroscopic polymer. We show stress sensitivity of around 20 kPanu0001u0003170 ppb of water vaporu0002 and subsecond response time for coated microbridges.